Vehicle-towed portable power-washing apparatus

ABSTRACT

The speed, effectiveness, and convenience with which pallets and other objects are cleaned can be increased by using a vehicle-towed portable pressure power-washing apparatus. The apparatus includes a platform that can be towed. On the platform is positioned at least one pressure-washer that pumps liquid from a tank into rotary arms within a cleaning chamber positioned on the platform, causing the rotation of the arms as the arms eject streams of the liquid pumped under a high pressure from angled nozzles. Belt conveyors carry an object in need of cleaning into the cleaning chamber, first exposing the object to the streams of the liquid, and then to a drying chamber. Guide rails positioned on the platform guide the object during cleaning, with the shape of one of the guide rails causing the object to fall off the platform following the drying to remove excess liquid left on the object.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional patent application claims priority under 35 U.S.C.§ 119(e) to U.S. Provisional Patent application, Ser. No. 62/527,892,filed Jun. 30, 2017 the disclosure of which is incorporated byreference.

FIELD

This application relates in general to tools for pressure-washing, andin particular, to a vehicle-towed portable power-washing apparatus.

BACKGROUND

A number of industries depend on pallets, flat structures that are oftenportable by a single person, for transport and storage of goods. Forexample, such pallets are used to transport and store a variety offoods, and are widely used by restaurants and grocery stores. Likewise,pallets are used in hospitals and other medical organizations forstorage of food, sterile goods, and lab supplies. Such pallets are oftenplastic, though other materials are also be used. As these industriesgrow, so does the number of pallets needed to support them, with oneestimate putting the number of pallets in service in the United Statesalone to be in the range of two billion.

Consequently to the enormous number of pallets used, replacement of apallet after a single use is impracticable due to prohibitive cost aswell as a negative environmental impact of such a practice. At the sametime, pallets used for transport and storage of materials requiring aparticularly high level of cleanliness, such as food and medicalsupplies, may no longer be suitable for that role after a single use dueto being too “dirty.” Such dirt can be a remainder of the material thatwas previously stored on the pallet, such as remainders of food orspilled laboratory media. Additionally, bacteria, including pathogenicbacteria, can colonize such remnants, or, even if no visible remnantswere left, bacteria present on one type of food, such as raw meat, maybe undesirable for another type of food, such as vegetables. Further, ifpallets are exposed to the elements either before or after use for anextended period of time, the exposure can promote accumulation of dustand soil on the pallets. Likewise, depending on the material of thepallets, exposure of pallets to moisture, such as during storage, maypromote mold growth on the pallets. Thus, before a pallet can be reused,or depending on storage conditions, used for the first time, the pallethas to be cleaned. As the number of pallets that are necessary for aparticular operation grows, the pressure to have the necessary palletsgrows as well.

Current pallet cleaning techniques lack in speed, effectiveness, andeconomic efficiency. For example, such pallets can be washed by hand andleft to air-dry after being washed. However, such a technique becomestoo slow and uneconomical as the number of pallets that need to becleaned grows, requiring excessive personnel hours to perform andpossibly requiring days for a single pallet to dry.

Pressure-washing, also known as power-washing, has also been used tospeed up cleaning of pallets. Power-washing involves spraying a liquidpumped at a high pressure at an object in need of cleaning. However,existing power-washing equipment has not proved adequate in addressingthe needs described above. For example, U.S. Pat. No. 6,129,099, issuedto Foster et al. on Oct. 10, 2000, the disclosure of which isincorporated by reference, discloses a method and apparatus for cleaningarticles such as pallets. The apparatus includes a washing chamber. Atthe entrance to the washing chamber is located a conveyor system, whichtransports the articles into and through the washing chamber. Adjustableguide rails support the article as the article passes through thechamber. The apparatus includes a high pressure pump supplying fluid atabout 1400 psi to spray arms and spray nozzles located in the chamber.In particular, the washing chamber includes fixed or rotating overheadnozzles that are located above the articles being carried by theconveyor belt. The spray arms located within the washing chamber arerotated by motors at a speed of 100-800 rpm and the fluid provided bythe pump is ejected from via nozzles as knife-like jet stream spray thatimpacts the surface of the article being washed at an angle of 10°-45°.The rotating spray arms may be positioned on the sides of the articlesbeing washed as well as above the articles and below the belt conveyors.The fluid used in the washing is collected in a tank and is subsequentlypumped to a filter assembly. Blower fans located within a drying chamberadjacent to the washing chamber blow air at the articles to dry themoff.

The Foster apparatus has multiple limitations. First, the pressuregenerated by the fluid pump, 1400 psi, may not be sufficient foreffectively cleaning certain kinds of dirt. In addition, as the Fosterapparatus uses nozzles located both on the sides, above, and possiblybelow the article being washed, the large number of nozzles limits thepressure under which the pump can simultaneously provide fluid to thenozzles and increases the amount of fluid that needs to be used in thewashing. Furthermore, while apparatus can be transported within the samebuilding using a set of casters on which the apparatus rests or using aforklift, transporting such an apparatus over longer distances in suchfashion becomes impracticable. Also, the apparatus receives power from astandard 240 v, three phase, electrical connection to function, thusgenerally being useful only inside a building with an electrical gridsufficient to support all of the elements of the apparatus. The burdenon the electrical grid is further increased due to the use of motors toimplement the rotation of the spray arms. Finally, the Foster apparatusrelies on gravity to filter the used water through the filters, whichlimits both the speed at which the filtration occurs and the degree ofpurification of the water, thus limiting the amount of pallets that canbe washed before clean fluid needs to be added to the apparatus.

Accordingly, there is a need for a way to quickly and efficiently cleanlarge numbers of objects such as pallets that can be performed in a widevariety of settings.

SUMMARY

The speed, effectiveness, and convenience with which pallets and otherobjects are cleaned can be increased by using a vehicle-towed portablepressure power-washing apparatus. The apparatus includes a platform thatcan be towed to a desired destination by a vehicle. On the platform isincluded at least one pressure-washer that pumps liquid from a tank intorotary arms within a cleaning chamber positioned on the platform,causing the rotation of the arms as the arms eject streams of the liquidpumped under a high pressure from angled nozzles. Belt conveyors carryan object in need of cleaning into two chambers, first exposing theobject to the streams of the liquid, and then to air blown into a dryingchamber by air blowers positioned on the platform. Guide railspositioned on the platform support the object during cleaning within thechambers, with the shape of one of the guide rails causing the object tofall off the platform following the drying to remove excess liquid lefton the object. Liquid used in the cleaning is collected, filtered, andrecirculated for further use using an angled grid within a liquidcollector within the chamber and a vacuum filtration unit positioned onthe platform. Additionally, pallets with certain configurations can bepre-washed using a portable wand connected to the pressure-washer.

In one embodiment, a vehicle-towed portable power-washing apparatus isprovided. The apparatus includes a portable platform including a vehiclecoupling; a liquid tank positioned on the platform; one or more pressurewashers positioned on the platform and connected to the liquid tank,each pressure washer including a gasoline-powered motor and ahigh-pressure pump that is driven by the motor and that pumps liquidfrom the liquid tank and pumps out the liquid into one or moreconnections under a high pressure. The apparatus further includes acleaning chamber positioned on the portable platform. The cleaningchamber includes: two walls substantially parallel to each other; twoswivel heads attached to each of the walls, each of the swivel headscomprising an end connected to one of the pressure washer connectionsand an opposite end comprising a rotatable hollow shaft; and two rotaryarms mounted on each of the swivel heads. Each of the arms includes arotatable hollow bar set onto the rotatable hollow shaft. Each of thearms further comprises a spray nozzle mounted upon each end of thehollow bar, the spray nozzles pointing into different directions,wherein the pump pushes the liquid through the connection connected tothat swivel head, the hollow bar of that arm, and out through the spraynozzles, causing an ejection of the liquid from the spray nozzles ofthat arm in a plurality of streams directed at an object within thewashing chamber, the ejection of the streams causing a rotation of thehollow bar and the rotatable hollow shaft. The apparatus furtherincludes one or more belt conveyors that carry the object in and out ofthe cleaning chamber.

Still other embodiments of the present invention will become readilyapparent to those skilled in the art from the following detaileddescription, wherein is described embodiments of the invention by way ofillustrating the best mode contemplated for carrying out the invention.As will be realized, the invention is capable of other and differentembodiments and its several details are capable of modifications invarious obvious respects, all without departing from the spirit and thescope of the present invention. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a vehicle-towed pressure-washing apparatusin accordance with one embodiment.

FIGS. 2A-2B show, by way of example, pallets of a particularconfiguration that may require pre-washing.

FIG. 3 is a diagram showing a portion of the inside of the cleaningchamber in accordance with one embodiment.

FIG. 4 is a diagram showing a cross-section view of the inside of thechamber in accordance with one embodiment.

FIG. 5 is a flow-diagram showing a method for use of the vehicle-towedportable power-washing apparatus of FIG. 1 in accordance with oneembodiment.

FIG. 6 is a diagram showing one of the arms set of the apparatus set ona swivel head in accordance with one embodiment.

FIG. 7 is a diagram showing a swivel head in accordance with oneembodiment.

FIG. 8 is a diagram showing a portion of the inside of the dryingchamber in accordance with one embodiment.

FIG. 9 is a diagram showing a cross-section view of the inside of thechamber in accordance with one embodiment.

DETAILED DESCRIPTION

While the apparatus described below references cleaning of pallets, theapparatus can also be used for cleaning of other objects. Further,pallets of a configuration different from the one shown in FIGS. 2A-2Bcan also be washed using the apparatus. While the objects being cleaned,such as pallets, can be made of plastic, objects made of other materialscan also be cleaned using the apparatus.

Portability of a cleaning apparatus can be increased by making theapparatus towable by a vehicle. FIG. 1 is a diagram showing avehicle-towed pressure-washing apparatus 10 in accordance with oneembodiment. The apparatus includes a portable platform 11 that includesa vehicle coupling 12 and can be towed by a vehicle. The vehiclecoupling 12 can be a trailer tongue that can attach to a trailer hitchon a vehicle, though other types of vehicle couplings 12 are alsopossible. In one embodiment, the vehicle can be an automobile, thoughother kinds of vehicles are also possible. In one embodiment, theplatform 11 is a trailer on wheels, though other kinds of portableplatforms suitable for transportation over a variety of terrains arepossible. A liquid tank 13 is located on the platform. In oneembodiment, the volume of the tank 13 can be 400 gallons, though othertank sizes are also possible. The liquid within the liquid tank can bewater, though other kinds of liquids, including various mixtures andsolutions, are possible. The liquid tank 13 is connected by a connection14 to at least one pressure washer 15 also located on the platform 11.The pressure washer 15 includes a motor and a high-pressure pump that isdriven by the motor. The pressure washer 15 further includes an unloadervalve for regulating the liquid flow and pressure within the pressurewasher. The motor can be a gasoline-powered motor, though other kinds ofmotors are also possible. In addition to driving the pump, the motor cangenerate electrical power that can be used to power other components ofthe apparatus 10, such as the belt conveyors 20-22. Other components inthe pressure washer 15 are possible. The pump pumps liquid from theliquid tank 13 via a connection 14 into a plurality of connections 16,17, 18 under a high pressure. In one embodiment, a single pressurewasher 15 is present on the platform 11. In a further embodiment,multiple pressure washers 15 can be present on the platform 11. Theconnections 16-18, as well as other connections described below throughwhich liquid and gases pass, can be flexible connections such as hoses,or rigid connections such as pipes, though other kinds of connectionsare also possible.

The connections 17, 18 connect the pressure washer 15 to a cleaningchamber 19 where objects that needs to be cleaned, such as pallets,undergo cleaning. As further described below with reference to FIG. 3,the chamber 19 includes two walls that are substantially parallel toeach other. On each of the walls are mounted two rotatory arms, each ofthe arms further including two spray nozzles mounted on the ends of thatarm. As further described below, the pressure washer 15 pumps the liquidunder a high pressure through the spray nozzles of the arms in aplurality of streams directed at an object being washed. The ejection ofthe liquid streams from the nozzles in turn causes a rotation of thespray arms, allowing the spray arms to spray the liquid at the objectfrom multiple positions. In one embodiment, the liquid is ejected fromeach of the nozzles at the rate of two gallons per minute under apressure of 4,000 psi. In a further embodiment, other numbers arepossible.

The apparatus 10 further includes one or more belt conveyors 20-22,which can be powered by the motor of the pressure washer 15, thoughother sources of power are possible. In particular, the belt conveyors20 and 21 are located partially within the cleaning chamber 19, with thebelt conveyor 20 bringing the objects that need to be cleaned into thecleaning chamber 19 and the belt conveyor 21 bringing the objects out ofthe chamber 19 after the object has been cleaned. The object can beinitially placed on the belt conveyor 20 to be brought into the cleaningchamber 19, such as by the personnel overseeing the cleaning.Alternatively, the apparatus 10 can include an additional belt conveyor22 at least a part of which is not located on the platform 11, but whichis proximate enough to the belt conveyor 20 to carry the object beingcleaned to the belt conveyor 20, thus allowing the object to betransported into the chamber 19. Thus, at least a part of the beltconveyor 22 could be attached to the platform 11 and hanging from theplatform 11. Alternatively, the belt conveyor 22 can be physicallydetached from the platform 11, but leaned against the platform 11 duringthe operation of the apparatus 10. Other ways in which the belt conveyor22 can pass the object to the belt conveyor 20 are possible. The beltconveyors 20-22 can each include a separate motor; in a furtherembodiment, at least some of the belt conveyors 20-22 can include ashared motor. The motors of the belt conveyors can have independentpower sources, be powered via an electrical connection (not shown) fromthe pressure washer 15, or be powered by the generator 30 describedbelow via an electrical connections (not shown).

In addition to the cleaning chamber 19, the apparatus further includes adrying chamber 91, into which the conveyor 21 carries the object beingcleaned after the object is cleaned in the cleaning chamber 19. Theapparatus further 10 includes at least one air blower 23, which can blowair via one or more connections 24 at the object in the drying chamber91 by removing at least some of the liquid left after using the sprayarms, as further described below with reference to FIGS. 8 and 9. Whilein FIG. 1, only one connection 24 is shown connecting to one side of thechamber 91, in a further embodiment, multiple connections 24 can connectto multiple sides of the chamber 91. The blower 23 can include at leastone fan that blows air through the connections 24. The air blower 23 canalso include an air compressor that generates the streams of air beingblown. Still other kinds of air blowers 23 are possible. In addition, atleast one suction fan 98 is included on the platform 11 and is connectedto the drying chamber 91 via a connection 99. The suction fan 99 createsa partial vacuum to suck up moisture from the drying chamber 91, such asby including an air pump (such as a centrifugal fan), though other waysto create the partial vacuum. The at least one suction fan 98 can bepowered by the pressure washer 15, through the connection 25 or througha connection that is wholly separate from the connection powering the atleast one blower 23. Other ways to power the suction fan 98 arepossible.

The chamber 91 can further include a window (not shown), which can beincluded on top of the chamber 91 to provide the heated air anadditional escape from the chamber 19. The blower 23 can be powered byan additional electric power generator 30 can be located on the platform11. The generator 30 can be a gasoline generator and be connected via aconnection 67 to a gasoline tank 31, though other kinds of generators 30are also possible. In a further embodiment, other sources of power forthe blower 23 are possible, such as the motor of the power washer 15.

While the use of the air blower 23 removes a significant amount of theliquid from the object being cleaned, some liquid tends to remain on theobject even after the air drying. While the amount of moisture removedcould be increased by increasing the time the object spends being airdried, such an increase would lead to a slowing of the rate at which theobjects are washed. To increase the rate at which the cleaned objectsdry without negatively affecting the cleaning speed, the apparatus 11includes at least two guide rails 26, 27. As further described belowwith reference to FIG. 3, the guide rails 26, 27 support the object suchas a pallet in the position for cleaning while the object travels on thebelt conveyors 20, 21. Whereas the portions of the guide rails 26, 27that guide the object before the object enters the cleaning chamber 19and after the object enters the cleaning chamber are substantiallyparallel with the walls of the cleaning chamber 19 and the dryingchamber 91, a portion of one of the guide rails 26, 27 traverses over aportion 65 of the belt conveyor 21. When the object such as a palletbeing carried by the belt conveyor 21 is pushed against the diagonalportion 65 of the guide rail 26, 27, the object tips over and falls fromthe belt conveyor 21. The impact of the fall shakes additional liquidfrom the object, minimizing the time that the object needs to be driedafterwards. While FIG. 1 shows the rail 27 as having the traverseportion 65, in a further embodiment the rail 26 can be the rail with thetraverse portion 65. Further, while only one of the rails 26, 27 isshown as extending from the side of the chamber 91 from which thecleaned object exits, in a further embodiment, the rail 26, 27 that doesnot have the traverse portion 65 can also extend from the chamber tomaintain the object in the proper position on the belt conveyor 21 untilthe object reaches the diagonal portion 65 of the guide rail. Inaddition, while only one guide rail 26 and one guide rail 27 is visiblein FIGS. 1, 3, and 8, multiple levels of guide rails 26, 27 can bevertically stacked, as shown with reference to FIGS. 4 and 9.

The apparatus 10 does not require a constant replenishment of the liquidin the liquid tank 13. As further described below with reference to FIG.3, the liquid used in the cleaning of the object inside the cleaningchamber 19 accumulates inside a liquid collector included in the chamber19, which includes an enclosure located beneath the belt conveyors. Theenclosure is in turn connected via a connection 28 to a vacuumfiltration unit 29 that uses vacuum to draw the liquid from the liquidcollector in the chamber 19 through one or more filters (not shown)located within the unit. Once filtered, the vacuum filtration unit 19pumps the filtered liquid into the liquid tank 13 via a connection 66,thus replenishing the liquid supply available for cleaning additionalobjects. While the amount of liquid removed from the object in thedrying chamber 91 is significantly less the amount of liquid that issprayed in the cleaning chamber 19, the drying chamber 91 can alsoinclude the enclosure connected to the vacuum filtration unit in thesame way as the cleaning chamber 19, as further described below withreference to FIG. 9. The vacuum filtration can be powered by thegenerator 30 via an electrical connection 68; alternatively, the vacuumfiltration unit can receive power from another source, such as by beingelectrically connected to the pressure washer 15 (electrical connectionnot shown).

The liquid being pumped by the pressure washer 15 can be manipulatedbefore being expelled through the spray nozzles. For example, the liquidcan be heated up as the liquid passes through the connections 17, 18from the pressure washer 15 into the cleaning chamber 19. Thus, at leastone boiler 32 can be located on the platform 11 and connected via aconnection 33 to one or more of the connections 17, 18, and can heat upthe liquid being pumped into the cleaning chamber 19 to increase theefficiency of the water. While in FIG. 1, the connection 33 interfacesonly to one of the connections 16, 17, 18 connection 18, in a furtherembodiment, the connection 33 could heat up the liquid pumped over twoor all of the connections 16, 17, and 18. The boiler 33 fan be poweredby diesel and can be connected via a connection 34 to a diesel tank 35from which the diesel is supplied, though other kinds of liquid heaters33 are possible. Further, a chemical injector 36, which can be poweredby the motor of the pressure washer 15 via an electrical connection 37,can be located on the platform 11. In a further embodiment, the injector36 can be powered by the generator 30 via an electrical connection (notshown). The injector 37 can inject via a connection 38 pre-loadedchemicals, such as soap, antibacterial and antifungal chemicals, orother cleaning chemicals, into the liquid being pumped into the cleaningchamber 19 via connections 17, 18, providing the liquid additionaldesired properties and improving the cleaning of objects such aspallets.

While the cleaning chamber 19 and the drying chamber 91 provide aneffective and efficient way of cleaning the pallets, some pallets may beof a shape that complicates cleaning of all external surfaces of suchpallet. FIGS. 2A-2B show, by way of example, pallets 40 of a particularconfiguration that may require pre-washing. As shown in FIG. 2A, apallet 40 may include grooves 41 along the sides, with some of thegroove surface being harder to reach with the liquid sprayed from thespray arms. The surfaces of the grooves 41 can be pre-washed using aportable wand 42 that is connected to the pressure washer 15 via aflexible connection 16. The wand 42 includes multiple hollow 43 rodsthrough which travels the liquid pumped by the pressure washer 15. Atthe end of each of the rods is set a rotatable nozzle 44. Each nozzle 44includes at least two openings 45 through which the liquid pumped by thepressure washer 15 is sprayed. A rotatable nozzle 44 is set on each ofthe rods 43, and the streams of the pumped liquid exiting from theopenings urges a rotation of the nozzles. For example, as furtherdescribed below, multiple pallets can be stacked on top of each other ina way that the grooves on the adjacent pallets 41 are aligned, forming apassage 46 through which the rods 43 of the wand 42 can be inserted, ascan be seen with reference to FIG. 2B. The number of the rods 43 on eachwand be customized for the type of pallet 41 being cleaned and can matchthe number of passages 46 formed by the grooves 41 when a pallet 40 isstacked on top of another pallet 40. When the rods 43 are insertedinside the passages, the pressure of the liquid streams ejected from theopenings of each of the nozzles causes each of the nozzles to rotate,with the rotation increasing the area cleaned by the spraying of theliquid. Other configurations of the pallets could include slots insteadof grooves 41, with the wand 42 being similarly capable of washing theslots aligned when the pallets 40 are stacked on top of each other.

While FIG. 1 shows the pressure washer 15 being connected to a singlewand 42, in a further embodiment, multiple wands 42 can besimultaneously present. Thus, the wands 42 can be simultaneously used.For example, if four or more pallets 41 are stacked on top of eachother, the rods 43 of at least two wands can be simultaneously insertedinto the at least two rows of passages 46 formed by the stacked pallets,allowing to clean the grooves of multiple sets of pallets 40simultaneously. When multiple wands 42 are thus used simultaneously, thewands 42 can be attached to a stand, portable or stationary, thus notrequiring constant human oversight of the cleaning.

In one embodiment, the machinery described above that is located on theplatform 11 can be turned off and on manually and run independently ofeach other. In a further embodiment, the machinery can be controlled viaelectrical connections by a micro-processor capable of executingcomputer-executable code. The micro-processor could be programmed toexecute particular programmed routines upon receiving a user commandduring which the pallets are exposed to particular cycles of beingsprayed with the liquid and dried under the fan.

As mentioned above, the majority of the washing and drying of thepallets takes place within the cleaning chamber. FIG. 3 is a diagramshowing a portion of the inside of the cleaning chamber 19 in accordancewith one embodiment. For the sake of clarity, the entrance to thechamber 19 is shown uncovered. In a further embodiment, the entrancecould be at least partially covered to prevent excess liquid fromspilling out from the chamber 19. Further, for the sake of clarity onlya portion of the platform 11 is shown and the optional belt conveyor 22is not shown.

On each of the walls 52 of the cleaning chamber 19 are mounted tworotatory arms 51. Each of the arms 51 is mounted to a swivel head 53that is attached to the wall 52. Each arm 51 includes a hollow bar 54 ateach end of which is set a spray nozzle 55. One side of the bar 54includes a threaded opening (not shown) that is fixedly set onto arotatable, threaded end of a swivel head 53. The rotatable portion ofthe swivel head 53 includes a hollow threaded shaft 84, shown withreference to FIG. 7, on which the hollow bar 54 is set and which freelyrotates with the bar 54 in relation to the remainder of the swivel head53. The opposite end of the swivel head 53 includes a stationary hollowrod 85 that is connected to one of the connections 17, 18, leading fromthe pressure washer 15, allowing fluid pumped by the pressure washer 15to enter the swivel head 53. The hollow rod 85 and the rotatable shaft84 are also connected via at least one passage in the body 86 of theswivel head 53, allowing the fluid pumped by the pressure washer intothe hollow rod to pass through the body 86 of the swivel head and enterinto the rotatable shaft 84. Through the rotatable shaft 84 the liquidcan flow into the hollow bar 54, eventually reaching the nozzles 55 andbeing ejected from the nozzles 55 under high pressure (such as 4,000psi, though other pressure is also possible). One or more O-rings can bepositioned on the threaded rotatable shaft 84 to promote a sealedcoupling of the hollow bar 54 to the swivel head 53 and to prevent thefluid from leaking. In one embodiment, the swivel head 53 can be aDYCI/DYDI swivel head manufactured by Mosmatic AG of Necker,Switzerland, though other kinds of swivel heads 53 are also possible. Ina further embodiment, additional nozzles could be positioned on portionsof the walls, with the liquid supplied by the pressure washer beingsprayed from those nozzles.

While the coupling of the hollow bar 54 and the swivel head 53 isdescribed above via the threads on the rotatable shaft 84 and the hollowbar 54, other ways for the coupling to be done are possible.

The connections 17, 18 swivel head 53, the hollow bar 54, and thenozzles 55 form a continuous conduit through which the liquid is pumpedby the pressure washer 15 under a high pressure, streams of the liquidexiting from the nozzles 55.

FIG. 6 is a diagram showing one of the arms 51 of the apparatus 10 inaccordance with one embodiment. As can be seen with reference to FIG. 6,the hollow bar 54 includes portions 81 are bent to the straight portion82 of the hollow bar 54. By being set on the bent portions 81, thenozzles 55 are at an angle relative to the straight portion 82 of thebar 54 in multiple dimensions. For purposes of clarity, athree-dimensional axis grid 88 is shown next to the arm 51. The grid 88includes a y-axis, along which coordinates along a vertical plane aremeasured; an x-axis, along which coordinates along a horizontal planeare measured; and a z-axis, along which depth is measured. The nozzles55 are angled with respect to the straight portion 82 of the bar 54along two planes. Thus, with the position of the arm 51 shown withreference to FIG. 6, the nozzles are at an angle along the z-axisrelative to the straight portion 81 of the bar 54. As can be seen withreference to FIG. 6, the nozzles are pointed into opposing directionsalong the z-axis. In one embodiment, each nozzle 55 deviates 15°-20° (ina direction opposite to the other nozzle) from the straight portion 82of the bar 54 along the z-axis, though other degrees of deviation arepossible. Further, the nozzles 55 are also at an angle with respect tothe straight portion 82 of the bar 54 along the y-axis, pointed towardseach other along the y-axis. In one embodiment, the nozzles are set atan angle of 35-50 degree along the y-axis with respect to the straightportion 82 of the bar 54, though other angles are possible. While in oneembodiment, the angles by which the nozzles 55 differ from the straightportion 82 of the bar 54 are the same for both nozzles 55 (even thoughthe nozzles are not pointed in the same direction), in a furtherembodiment the angles can be different. The description of the positionof the nozzles 55 above is in reference to the orientation of the arm 51shown in FIG. 6, and the directions in which the nozzles 55 point wouldchange along with a change in the orientation of the arm 51.

The expulsion of the stream of the liquid from the angled nozzles 55 atthe high pressure causes the rotational movement of the bars 54 (andconsequently of the nozzles and of the rotatable shaft of the swivelhead 53) regardless of whether the stream of water hits the pallet 41due to the water streams being expelled from the nozzles in differentdirections, thus allowing to avoid having a separate motor to rotate thearms 51. In one embodiment, the speed of the rotation can be between1500 and 2000 rpm, though other rotation speeds are also possible. Thus,the apparatus does not require use of additional motors for rotation ofthe arms 51, saving power.

The angling of the nozzles 55 allows to cover multiple surfaces of theobject being washed, including the top surface, and thus not requiringan installation of additional nozzles on top of the object. In addition,the positioning of the belt conveyors allows the washing of the bottomsurface of the object. As mentioned above, portions of the beltconveyors 20 and 21 are included within the chamber 19. The beltconveyors 20 and 21 do not join into a continuous belt conveyor, butrather a gap 81 exists between the conveyors 20, 21. The gap 81 is smallenough for an object such as a pallet 40 to pass over the gap 81 andtransition from being carried by the belt conveyor 20 to being carriedby the belt conveyor 21. When passing over the gap 81, the surface ofthe pallet 40 that is pressed against the belt conveyors 20, 21 at othertimes is exposed to the liquid stream being ejected from the anglednozzles 55 when the nozzles 55 are located below the level of thatsurface during the rotation of the rotary arms 51. Due to the angled,spray nozzles 55 being able to spray liquid at all surfaces of theobject being washed, including the top and the bottom surfaces,apparatus does not need to include nozzles located above and below theobject. By reducing the number of nozzles needed to wash all sides ofthe object, the pressure of liquid delivered through the nozzles and thespeed of the rotation of the nozzles can be increased, in turnincreasing the effectiveness of the cleaning. In addition, by reducingthe number of nozzles needed for the cleaning, the volume of the waterpumped through each of the nozzles can be increased, resulting in agreater cleaning action.

The guide rails 26, 27 help support the pallet 40 in place while thepallet 40 moves on the conveyor 20 and 21. The guide rails 26, 27 can beattached to the walls of the chamber 19 and the chamber 91 or to thebelt conveyors. In one embodiment, the guide rails 26, 27 can be fixedlyattached to the walls of the chamber 19 and the chamber 91 or to astationary portion of the belt conveyors 20, 21. In a furtherembodiment, the position of the rails 26, 27 can be adjustable. In oneembodiment, the portions of the guide rails 26, 27 within the chambers19 and 91 are diagonally placed in relation to the pallet 40. Thus, asthe pallet 40 is carried by the belt conveyors 20, 21 along the guiderails 26, 27 towards the exit 83 from the chamber 19, the portions ofthe pallet 40 that are shielded from the liquid streams ejected from thenozzles 55 are not the same when the pallet is at different points ofthe conveyor belts due to the diagonal rails. In a further embodiment,the orientation of the guide rails 26, 27 in the chamber 91 can differfrom the orientation in the chamber 19. In a still further embodiment,other orientations of the rails 26, 27 are possible.

To increase the area covered by the liquid streams ejected by the rotaryarms 51, the two rotary arms 51 on each of the walls of the chamber 19are not mounted on the same horizontal plane. FIG. 4 is a diagramshowing a cross-section view of the inside of the chamber 19 inaccordance with one embodiment. As can be seen with reference to FIG. 4,one of the rotary arms 51 is set lower than the rotary arms 51 on thesame wall. In a further embodiment, the heights at which the arms 51 areset can be different from the heights shown in FIG. 4. Further, asmentioned above, the chamber 19 includes a liquid collector 57 locatedbelow the belt conveyors 20, 21 and into which most of the liquid 58ejected from the rotary arms 50 collects. The collector 57 includes anenclosure 59 into which the liquid 58 collects. The collector 57 furtherincludes a floor 60 tilted at an angle. As shown in FIG. 4, the space 82between the tilted floor 60 and the bottom of the enclosure 59 caneither be empty, or filled with some material.

An angled grid 61 is positioned on the floor 60, the grid 61 being madeof multiple sheets 62. Each of the sheets 62 spans from one end of theenclosure 59 to another, preventing the liquid 58 from bypassing thesheet 62 except by going above the sheet 62. In one embodiment, thesheets 62 can be metal sheets fixedly attached to the floor 60, thoughother kinds of sheets are possible. Above the level of the sheets 62, apassage 63 is formed in the enclosure 57 that connects the enclosure 57to the connection 28 and to the vacuum filtration unit 29. The vacuumcreated by the vacuum filtration unit 29 draws the liquid 58 from theunit 29 into the connection 28. Due to the angling of the floor 60, thetop of the sheets located closer to the passage 63 extend higher thanthe tops of the sheets 62 located further from the passage.

The angled grid 61 helps to prevent undissolved dirt washed off thepallet 40 from entering the passage 63 leading to the filtration unit29, and thus helps to prevent the dirt from contaminating the vacuumfiltration unit 29, extending the unit's 29 longevity. In particular,when the liquid 58 is drawn towards the passage 63, the movement of theundissolved dirt is hindered by the sheets, promoting the sedimentationof the dirt either on the sheets 62 or in the area between the sheets62. Due to the angling of the floor 60, the top of the sheets locatedcloser to the passage 63 extend higher than the tops of the sheets 62located further from the passage 63, making progressively harder for thedirt to get over the sheets 62 that are closer to the passage 63. Inaddition, as the passage 63 is located above the level of the floor 60,the undissolved dirt that travels past the highest of the sheets 63 hasan increased chance of settling on the bottom on the floor 60 beforeentering the passage, further reducing the amount of the dirt enteringthe passage 63.

Once an object has been washed in the cleaning chamber, the conveyor 21carries the object into the drying chamber 91. FIG. 8 is a diagramshowing a portion of the inside of the drying chamber 91 in accordancewith one embodiment. For the sake of clarity, the entrance to thechamber 91 is shown uncovered. In a further embodiment, the entrancecould be at least partially covered to prevent liquid from spilling outfrom the chamber 91. Further, for the sake of clarity only a portion ofthe platform 11 is shown and connections, such as connections 24, 99, tothe outside of the chamber are not shown.

The drying chamber 91 includes a pipe 92 that is connected via aconnection 94 to one of the connections 24 to one or more of the blowers23 and is positioned between the guide rails 26, 27 on the walls 96 ofthe chamber 91. The pipe 92 further includes a slit 93 through which theblown by the one or more blowers 23 via the pipe 92 and the connection24 exits. The slit 93 is positioned on the surface of the pipe 92 facingthe object being dried as the object is carried by the conveyor 21through the chamber. The pipe 92 is positioned diagonally above theconveyor belt 21 so that the air from the slit 93 is blown at differentportions of the object as the object is carried through the chamber 91by the conveyor belt 21. The pipe 92 is attached to a connector pipe 94,which both physically secures the pipe 93 in place, and connects thepipe 92 to the connection 24 through which air is supplied by the atleast one blower 23 into the pipe.

The chamber 91 further includes a connection 95, which interfaces thechamber to the connection 99 and consequently, the at least one suctionfan 99. Through the connection 95, at least a portion of the moisturethat is in the air within the drying chamber 91 is suctioned off by theat least one suction fan 99, promoting drying off of the object in thechamber. In one embodiment, the moisture can be suctioned off at thesame time as air is blown through the slit 93 of the pipe 93. In afurther embodiment, the blowing of air through the slit 93 and thesuctioning off of the moisture is conducted at separate times. While theconnection 95 is shown with reference to FIG. 8 to be located at theexit 97 from the chamber 91, in a further embodiment, other positionsfor the connection 95 is possible.

The positioning of the pipe 92 within the chamber 91 maximizes theexposure of the object being dried to the air being blown from the slit93. FIG. 9 is a diagram showing a cross-section view of the inside ofthe chamber 91 in accordance with one embodiment. As can be seen withreference to FIG. 9, the pipe 92 is located of between the guide rails26 and the guide rails 27 (not shown in FIG. 9). Further, as mentionedabove, the chamber 91 can include a liquid collector 57 located belowthe belt conveyor 21 and into which most of the liquid 58 coming offfrom the object being dried collects and is removed from the chamber 91via vacuum filtration, as further described above with reference to FIG.4. In a further embodiment, the collector 57 could be absent from thechamber 91 and any liquid removed from the object being dried could landon a horizontal floor of the chamber. While the connection 28 to thevacuum filtration unit 29 is shown as passing through the cleaningchamber 19, in a further embodiment, the connection 28 of the dryingchamber 91 to the vacuum filtration unit 19 could bypass the cleaningchamber.

The use of the apparatus 10 allows to perform a quick and efficientcleaning of pallets at any place that is accessible to a vehicle. FIG. 5is a flow-diagram showing a method 70 for use of the vehicle-towedportable power-washing apparatus 10 of FIG. 1 in accordance with oneembodiment. Optionally, if the apparatus 10 is already not in a requiredlocation, the apparatus 10 is towed by a vehicle to the location wherethe cleaning needs to be performed, such as to a site of a restaurant,hospital, or another establishment in need of cleaned pallets (step 71).Also optionally, depending on pallet 40 configuration, pallets arestacked on top of each other so that the grooves 41 between the adjacentpallets 40 are aligned, and the passages 46 formed by the grooves of thepallets are washed by insertion of rods 43 of the wands 42 into thepassages 46, as further described above with reference to FIG. 1 (step72). Following the optional washing of the grooves, the objects beingwashed, such as pallets 40 are loaded onto either belt conveyor 20 (orbelt conveyor 22 if the belt 22 is present), with the belt conveyors 20,22 bringing the pallets 40 into the cleaning chamber 19, where thepallets 40 are washed and dried as described above, and the beltconveyor 21 bringing the pallets 40 out of the chamber 19 until thepallet fall off due to the impact with the diagonal portion of one ofthe rails 26, 27 (step 73). In one embodiment, the objects can be loadedonto the belt conveyor 20, 22 manually by an operator of the apparatus10. In a further embodiment, the objects can be loaded using theautomatic pallet feeder (not shown). The objects dropped from theapparatus 10 are then collected, either for reuse or for additionaldrying (step 74), ending the method 70. In one embodiment, thecollection can be done manually by the operator; in a furtherembodiment, the collection can be done using machinery such an automaticpallet stacker/dispenser.

While the invention has been particularly shown and described asreferenced to the embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A vehicle-towed portable pressure-washingapparatus, comprising: a portable platform comprising a vehiclecoupling; a liquid tank positioned on the platform; one or more pressurewashers positioned on the platform and connected to the liquid tank,each pressure washer comprising a gasoline-powered motor and ahigh-pressure pump that is driven by the motor and that pumps liquidfrom the liquid tank and pumps out the liquid into one or moreconnections under a high pressure; a cleaning chamber positioned on theportable platform, the cleaning chamber further comprising: two wallssubstantially parallel to each other; and one or more swivel headsattached to each of the walls, each of the swivel heads comprising anend connected to one of the connections and an opposite end comprising arotatable hollow shaft; one rotary arm mounted on each of the swivelheads, each of the arms comprising a hollow rotatable bar set onto therotatable hollow shaft, each of the hollow bars comprising asubstantially straight central portion and a bent portion formed on eachof the ends of the substantially straight central portion, wherein thebent portions are offset from the substantially straight central portionwith respect to two axis, each of the arms further comprising a spraynozzle mounted upon an end of each of the bent portions of the hollowbar and angled relative to the substantially straight central portion inthe two axis, the angled spray nozzles pointing into differentdirections, wherein the pump pushes the liquid through the connectionconnected to that swivel head through the hollow bar of that arm, andthrough the angled spray nozzles of that arm, causing an ejection of theliquid from the angled spray nozzles of that arm in a plurality ofstreams directed at an object within the cleaning chamber, and whereinthe ejection of the streams from the angled spray nozzles causes arotation of that arm and the rotatable hollow shaft upon which thehollow rotatable bar of that arm is set; and a plurality of beltconveyors that carry the object in through, and out of the cleaningchamber, the object having a plurality of surfaces, the surfacescomprising a bottom surface, a top surface, and side surfaces, whereintwo of the plurality of the belt conveyors are separated by a gap,wherein the liquid ejected from one or more of the angled spray nozzleshits at least a portion of the bottom surface of the object when theobject passes over the gap and wherein the liquid ejected from one ormore of the angled spray nozzles hits at least a portion of each of theremaining ones of the plurality of surfaces of the object as the objectis carried through the cleaning chamber by one or more of the pluralityof belt conveyors.
 2. A vehicle-towed portable pressure-washingapparatus according to claim 1, wherein each of the angled spray nozzleson each of the arms points towards a center of the straight centralportion of the hollow bar of that arm with respect to one of the axis.3. A vehicle-towed portable pressure-washing apparatus according toclaim 1, wherein the angled spray nozzles on each of the arms arepointed at an angle of 15°-20° relative to the central portion of thehollow bar of that arm in one of the two axis and 35°-50° relative tothe central portion of the hollow bar of that arm in another one of thetwo axis.
 4. A vehicle-towed portable pressure-washing apparatusaccording to claim 1, wherein the rotation of the arms is causedexclusively by the ejection of the streams from the angled spraynozzles.
 5. A vehicle-towed portable pressure-washing apparatusaccording to claim 1, further comprising: at least one pair of guiderods extending within the chamber and between which the object ispositioned while carried by the one or more belt conveyors.
 6. Avehicle-towed portable pressure-washing apparatus according to claim 5,wherein one end of each of the guide rods is higher than another end ofthat guide rod relative to the one or more belt conveyors.
 7. Avehicle-towed portable pressure-washing apparatus according to claim 5,wherein the object comprises a rectangular pallet and one or more swivelheads attached to each of the walls comprise two of the swivel heads andone of the swivel heads is lower on one of the walls than another one ofthe swivel heads on that wall.
 8. A vehicle-towed portablepressure-washing apparatus according to claim 1, further comprising: oneor more air blowers positioned on the platform; a drying chamber intowhich the one or more of conveyor belts carry the object upon the objectexiting from the cleaning chamber, the drying chamber furthercomprising: a pipe positioned above one or more of the conveyor beltswithin the chamber, the pipe comprising a slit on a surface of the pipethat faces the object when the object is carried through the chamber,wherein the one or more blowers are connected to the pipe and at least aportion of the air blown by the one or more blowers exits the slit andis directed at the object when the object is aligned with the shapedpipe.
 9. A vehicle-towed portable pressure-washing apparatus accordingto claim 8, a further guide rod positioned on a side of the chamber fromwhich the object exits the drying chamber, the further guide rodcomprising a portion parallel to the belt conveyor on which the objectexits the chamber and a portion traversing the belt conveyor the objectbeing pressed against the portion traversing the belt conveyor by thebelt conveyor causing the object to fall off the belt conveyor.
 10. Avehicle-towed portable pressure-washing apparatus according to claim 8,further comprising: one or more suction fans interfaced to the dryingchamber and configured to suction moisture from the drying chamber. 11.A vehicle-towed portable pressure-washing apparatus according to claim1, wherein the one or more air blowers are powered by an at least onegas powered generator and wherein the liquid exits each of the angledspray nozzles at a rate of two gallons per minute.
 12. A vehicle-towedportable pressure-washing apparatus according to claim 11, furthercomprising: at least one electrical power generator positioned on theplatform; and a fuel tank connected to the at least one electrical powergenerator from which the at least one electrical power generatorreceives fuel.
 13. A vehicle-towed portable pressure-washing apparatusaccording to claim 1, wherein at least some of the one or moreconnections are between the pump and the swivels, further comprising: aboiler interfaced to one or more of the at least some of the one or moreconnections between the pump and the swivels and adapted to heat up theliquid pumped through the connections; and a fuel tank connected to theboiler from which the boiler receives fuel.
 14. A vehicle-towed portablepressure-washing apparatus according to claim 1, further comprising: achemical injector connected to the at least some of the one or more ofconnections between the pump and the swivels and adapted to inject oneor more chemicals into the liquid pumped through the at least some ofthe one or more connections.
 15. A vehicle-towed portablepressure-washing apparatus according to claim 1, further comprising: aliquid collector positioned below the belt conveyors in the cleaningchamber into which at least a portion of the liquid sprayed at theobject collects after being sprayed at the object, the collectorcomprising an enclosure within which the collected liquid is contained;and a vacuum filtration unit connected to the liquid collector enclosurevia a vacuum line and further connected to the water tank and adapted todraw the liquid from the liquid collector through a filtering chamber,and to pump the filtered liquid into the liquid tank.
 16. Avehicle-towed portable pressure-washing apparatus according to claim 15,further comprising: an angled grid positioned within the enclosure andcomprising a plurality of sheets positioned at an angle relative to theenclosure, wherein at least a portion of the liquid within the collectoris drawn over one or more of the sheets, urging a sedimentation ofparticles removed by the liquid from the object onto the sheets.
 17. Avehicle-towed portable pressure-washing apparatus according to claim 16,wherein the enclosure comprises an angled floor on which the sheets arelocated.
 18. A vehicle-towed portable pressure-washing apparatusaccording to claim 1, further comprising: at least one portable cleaningwand connected to the pump, the wand comprising a plurality of hollowrods, a rotatable spray nozzle mounted on each end of each of the rods,the nozzle comprising a plurality of orifices through which the liquidis ejected in a plurality of streams directed at one or more objectsoutside the washing chamber, the ejection urging a rotation of the spraynozzles around the hollow rods.
 19. A vehicle-towed portablepressure-washing apparatus according to claim 18, wherein the objectscomprise at least two pallets stacked on top of each other, each of thepallets comprising a plurality of grooves and the wand rods and spraynozzles are shaped to insert between the grooves when the pallets arestacked.
 20. A vehicle-towed portable pressure-washing apparatusaccording to claim 1, wherein the one or more pressure washers comprisetwo of the pressure washers and each of the pressure washers isconnected to the rotary arms of one of the walls.